I'm getting error "Your campaign could not be submitted. Try submitting it again. If the problem persists, contact iAd." on submitting campaign

Hello,

I've setup a iAd campaign and all its required details but when I click on submit campaign on Summary tab it gives me an error "Your campaign could not be submitted. Try submitting it again. If the problem persists, contact iAd.".

Kindly let me know how to fix it or what I'm doing wrong.

Thank you.